The present invention relates to a method of locating abnormal originals which should be distinguished from normal originals in the process of photographic print exposure control. The term "abnormal originals" as used herein means those originals that have been deteriorated by the effects of high temperature, high humidity, gases and as a result of extended storage, as well as those which are produced by photography with unusual light sources such as fluoroescent lamps, tungsten lamps and setting sun light. The term "originals" means original negatives for negative-positive photography and original positives for positive-positive photography, but for convenience the following description is made with reference to negative-positive photography.